"Time to let the world know," he posted, a day ahead of schedule. "My next destination is Manchester United #IAmComing."
A free agent after his exploits at Paris Saint-Germain, he fulfilled an ambition to play in the Premier League, at the age of 34, and instantly started imposing his huge personality around the place.
Handed the no.9 shirt, the experienced centre-forward was reunited with Jose Mourinho, after previously playing under him at Internazionale.
In his first interview with club media, Zlatan said: "I am absolutely delighted to be joining United and am looking forward to playing in the Premier League.